European patent application No. 0 149 088 describes analgesically active compounds having the formula ##STR2## wherein the radicals R.sub.1 and R.sub.2 are the same or different and represent hydrogen, halogen atoms, a trifluoromethyl group, a cyano group, a nitro group, an amino group, a mono-C.sub.1 -C.sub.6 -alkylamino group, a di-C.sub.1 -C.sub.6 -alkylamino group, an amino group that is substituted by a phenyl radical, a mono or dihalogenphenyl radical or a phenyl-C.sub.1 -C.sub.4 -alkyl radical, a C.sub.1 -C.sub.6 -alkanoylamino group, a C.sub.1 -C.sub.6 -alkoxycarbonylamino group, a C.sub.1 -C.sub.6 -alkyl group optionally substituted by a phenyl radical, a phenyl group, a hydroxy group, a C.sub.1 -C.sub.6 -alkoxy group, a phenoxy group, a carboxy group, a carb-C.sub.1 -C.sub.6 -alkoxy group or a carbamoyl group optionally substituted by one or two C.sub.1 -C.sub.6 -alkyl groups, the radical R.sub.3 is hydrogen, a C.sub.1 -C.sub.6 -alkyl group, a C.sub.3 -C.sub.6 -alkenyl group, a C.sub.3 -C.sub.6 -alkynyl group, a C.sub.3 -C.sub.7 -cycloalkyl group, a C.sub.5 -C.sub.7 -cycloalkenyl group, a phenyl-C.sub.1 - C.sub.4 -alkyl group, a carb-C.sub.1 -C.sub.6 -alkoxy group, a C.sub.2 -C.sub.6 -alkanoyl group optionally substituted by a C.sub.3 -C.sub.6 -cycloalkyl radical or a C.sub.1 -C.sub.4 -alkyl group which has at the same carbon atom two C.sub.1 -C.sub.6 -alkoxy groups or a C.sub.2 -C.sub.4 -alkylenedioxy group or wherein R.sub.3 is a C.sub.1 -C.sub.6 -alkyl group which is substituted once or twice by C.sub.3 -C.sub.7 -cycloalkyl groups, hydroxy groups C.sub.1 -C.sub.6 -alkoxy groups, halogen atoms, sulfo groups (--SO.sub.3 H), amino groups, C.sub.1 -C.sub.6 -alkylamino groups, di-C.sub.1 -C.sub.6 -alkylamino groups, C.sub.1 -C.sub.6 -alkylcarbonyl groups, C.sub.3 -C.sub.7 -cycloalkylcarbonyl groups, carb-C.sub.1 -C.sub.6 -alkoxy groups or benzoyl groups, X represents oxygen, sulphur, SO or SO.sub.2, Alk is alkylene with 0-4 carbon atoms and n and m are the same or different and can represent the numbers 1-3, wherein n can also be 0 when Alk is alkylene with at least one carbon atom and m in this case represents the numbers 2-6 and where the grouping ##STR3## can also represent the quinuclidyl radical or the tropanyl radical.